I have an older iPad and it won't let me access or use my funds in my itune store. Spent 1 1/2 hours..

I have an older iPad and it won't let me access or use my funds in my itune store. Spent 1 1/2 hours on the phone with tech trying to figure it out. Basically, I can log in on another device and try but I see nowhere to actually log out of Wildcraft and no where to find out my username and password. Suggestions?